Premium
Surfactant and inhaled particles in the conducting airways: Structural, stereological, and biophysical aspects
Author(s) -
Gehr Peter,
Geiser Marianne,
Hof Vinzenz Im,
Schürch Samuel,
Waber Urs,
Baumann Markus
Publication year - 1993
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.1070260510
Subject(s) - pulmonary surfactant , inhalation , surface tension , particle (ecology) , inhalation exposure , chemistry , materials science , biophysics , anatomy , medicine , biochemistry , physics , oceanography , quantum mechanics , biology , geology
We have investigated the displacement into the sol phase of inhaled particles deposited in the intrapulmonary conducting airways. Hamsters inhaled an aerosol of monodisperse polystyrene particles of 6 μm diameter. Their lungs were fixed by intravascular perfusion, and light and electron microscopy was used to study the epithelial coating. The surfactant film at the wall‐air interface was investigated by measuring its surface tension. The number of particles retained was determined stereologically. In addition we investigated the displacement of spherical particles in vitro on a DPPC monolayer in a Langmuir‐Wilhelmy surface balance and determined the surface tension in vivo in the horse trachea by video bronchoscopy, applying the droplet spreading method. We found that particles deposited onto a surfactant film were pulled into the aqueous subphase, and we concluded that surface forces due to the airway surfactant likely displace deposited particles into the periciliary fluid (sol phase). Comparing lungs fixed immediately after inhalation with lungs fixed 24 hr after inhalation revealed that 86% of the particles retained in the intrapulmonary conducting airways immediately after inhalation had been cleared within 24 hr. One‐third of the particles of the lungs fixed immediately after inhalation was phagocytized. The combination of structural and stereological analyses with in vitro and in vivo measurements has led to new insights into the role of airway surfactant with respect to the fate of inhaled particles, which may have important consequences regarding the effects of hazardous particles, which may have important consequences regarding the effects of hazardous particles. These studies may also help to evaluate the deposition pattern and clearance of therapeutic particles, with important implications for their therapeutic use. © 1993 Wiley‐Liss, Inc.